Double fertilization is a complex fertilization mechanism of flowering plants. This process involves the joining of a female gametophyte with two male gametes. It begins when a pollen grain adheres to the stigma of the carpel, the female reproductive structure of a flower.
        
                    
             
        
        
        
includes the brain and spinal cord
 
        
                    
             
        
        
        
Answer:
The nerves in the integumentary system (skin) sense the irritation and send the signal to the brain. The brain then sends impulses through the nervous system to scratch the itch.
Explanation:i hope this helps u :)
 
        
             
        
        
        
There are mountain ranges in the middle of the ocean floor. Because of the higher elevation gravity pushes down on the edges of the plates. This is called ridge push.
<h3><u>Explanation:</u></h3>
Ridge push is a simple explanation of the height of the landforms based on the gravity and the elasticity of the underlying rock. It says when a landform gets too much higher, the weight of the overlying rock and soil pushes the landform back to plains. Thereby an equilibrium is maintained.  
Slab pull is a theory proposed which visualizes the earth interior as a pool of hot molten lava that has a convection current going on. It explains why the crust of the earth continuously moves slowly and forms mountains and other rift valleys.  
 
        
             
        
        
        
Answer:
Gene, a part of DNA that determines the trait of individual characteristics
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